Quick answer
Lucena Position is an endgame technique: Lucena bridge-building. Work from the first evidence position for Lucena Position, and begin by testing Kh7.
Begin from Kh7 in 2Q5/6k1/2K5/5R2/8/8/8/7r b - - 4 3. Count the material, king routes, promotion squares and reserve tempi before applying a theoretical rule. The evidence answer is: Lucena Position: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kh7.
In the Lucena Position example, notice: side Black; pieces White queen c8, Black king g7, White king c6, White rook f5, Black rook h1; legal first moves Kh7, Kh6, Kg6, Rh2, Rh3, Rh4, Rh5, Rh6+. Use the inventory as a reading aid for this position alone rather than as a template for other games.
Material and result question
The first evidence board tests Lucena bridge-building; the second board tests Lucena bridge-building. A is seeded by the moves direct FEN setup. B is seeded by direct FEN setup. Definitions for adjacent ideas are on the Chess Wiki and the Endgames hub. Then compare Material Values with Cut Off King In Rook Endings, Philidor Position, Vancura Defense around the king's route around a pawn chain.
The two inventories make the distinction concrete. A contains side Black; pieces White queen c8, Black king g7, White king c6, White rook f5, Black rook h1; legal first moves Kh7, Kh6, Kg6, Rh2, Rh3, Rh4, Rh5, Rh6+; B contains side White; pieces Black king h8, White pawn c7, Black rook g7, White king c6, White rook b1; legal first moves c8=N, c8=B, c8=R+, c8=Q+, Kb7, Kd6, Kd5, Kc5. Compare the side to move before comparing the labels in the context of king opposition on the critical file.
Topic dossier for this page and board pair r1:2Q5 | r2:6k1 | r3:2K5 | r4:5R2 | r5:8 | r6:8 | r7:8 | r8:7r / r1:7k | r2:2P3r1 | r3:2K5 | r4:8 | r5:8 | r6:8 | r7:8 | r8:1R6: start with the king's route around a pawn chain; then test king opposition on the critical file; keep a knight route that changes the blockade separate from the moment to trade the last pawn; use a stalemate resource as the transfer check; and reserve a theoretical draw with practical tests for the exception.
Conversion or defense plan
On the first board, calculate Kh7 after Kh7 and write down the opponent's best reply around the king's route around a pawn chain. On the second board, calculate Kc5 after Kc5 and check king opposition on the critical file. Separate the practical conversion question from the result question; side to move and one checking distance can change the conclusion. In this case the useful condition is a theoretical draw with practical tests.
Key claim: Lucena Position is illustrated here by Lucena bridge-building; the first concrete test is Kh7. The board anchor is 2Q5/6k1/2K5/5R2/8/8/8/7r; the example is intentionally narrower than the topic label and should not be generalised without checking the surrounding position..
Practical boundary: To answer “What exact king, pawn, and move-order conditions decide lucena position, and how should each side play them?”, compare the recorded setup with Kc5 and the opponent's reply. The decision is useful only when the stated condition survives that concrete test on board 7k/2P3r1/2K5/8/8/8/8/1R6. The evidence records No tablebase outcome is asserted by this generated record; verify the exact FEN before publication and the second board signature r1:7k | r2:2P3r1 | r3:2K5 | r4:8 | r5:8 | r6:8 | r7:8 | r8:1R6. The false-positive test is whether a knight route that changes the blockade appears without the moment to trade the last pawn, so the conclusion is useful only when the stated condition survives that concrete test.
Evidence positions
example-1: Lucena bridge-building
Show answer
Lucena Position: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kh7.
Why this position is here: Lucena Position is represented by Lucena bridge-building. This is a direct FEN setup with board anchor 2Q5/6k1/2K5/5R2/8/8/8/7r; no opening history is inferred from the diagram.
FEN: 2Q5/6k1/2K5/5R2/8/8/8/7r b - - 4 3
Question: What is the first concrete decision in this lucena position position?
Answer cue: Lucena Position: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kh7. The first candidate to test is Kh7. Replay Kh7 on board anchor 2Q5/6k1/2K5/5R2/8/8/8/7r and write down what changes after it.
Evidence boundary: No tablebase outcome is asserted by this generated record; verify the exact FEN before publication.
example-2: Lucena bridge-building
Show answer
Lucena Position: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kc5.
Why this position is here: Lucena Position is represented by Lucena bridge-building. This is a direct FEN setup with board anchor 7k/2P3r1/2K5/8/8/8/8/1R6; no opening history is inferred from the diagram.
FEN: 7k/2P3r1/2K5/8/8/8/8/1R6 w - - 2 2
Question: What is the first concrete decision in this lucena position position?
Answer cue: Lucena Position: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kc5. The first candidate to test is Kc5. Replay Kc5 on board anchor 7k/2P3r1/2K5/8/8/8/8/1R6 and write down what changes after it.
Evidence boundary: No tablebase outcome is asserted by this generated record; verify the exact FEN before publication.
example-3: Lucena bridge-building
Show answer
Lucena Position: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Ra8.
Why this position is here: Lucena Position is represented by Lucena bridge-building. This is a direct FEN setup with board anchor 2Nr4/6k1/8/1K6/8/8/R7/8; no opening history is inferred from the diagram.
FEN: 2Nr4/6k1/8/1K6/8/8/R7/8 w - - 1 4
Question: What is the first concrete decision in this lucena position position?
Answer cue: Lucena Position: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Ra8. The first candidate to test is Ra8. Replay Ra8 on board anchor 2Nr4/6k1/8/1K6/8/8/R7/8 and write down what changes after it.
Evidence boundary: No tablebase outcome is asserted by this generated record; verify the exact FEN before publication.
Reading the line
Read the first example (id example-1) as a complete record: continuation Kh7, source tablebase. This is a direct FEN setup with board anchor 2Q5/6k1/2K5/5R2/8/8/8/7r; no opening history is inferred from the diagram. If A does not expose Lucena bridge-building, correct the evidence before relying on the prose.
Read the second example (id example-2) separately: continuation Kc5, source tablebase. Its feature is Lucena bridge-building; inventory side White; pieces Black king h8, White pawn c7, Black rook g7, White king c6, White rook b1; legal first moves c8=N, c8=B, c8=R+, c8=Q+, Kb7, Kd6, Kd5, Kc5. Compare what changes between Kh7 and Kc5.
Boundary cases
The main mistake to avoid with Lucena Position is applying a remembered endgame rule while ignoring side to move, king placement or an unverified result. In A, the missing condition must be located in r1:2Q5 | r2:6k1 | r3:2K5 | r4:5R2 | r5:8 | r6:8 | r7:8 | r8:7r after Kh7; in B, test it against r1:7k | r2:2P3r1 | r3:2K5 | r4:8 | r5:8 | r6:8 | r7:8 | r8:1R6 after Kc5.
For Lucena Position, the first board's evidence boundary (after Kh7) is No tablebase outcome is asserted by this generated record; verify the exact FEN before publication. The second board's evidence boundary for Lucena Position is No tablebase outcome is asserted by this generated record; verify the exact FEN before publication. If a trusted source or careful calculation changes the conclusion around a stalemate resource, update both the evidence record and this article.
Practice from a real game
play the position for both sides, record the critical tempo, and verify the exact FEN against the cited tablebase before publication. Start with A's side to move and r1:2Q5 | r2:6k1 | r3:2K5 | r4:5R2 | r5:8 | r6:8 | r7:8 | r8:7r; record two candidates, the reply to Kh7 and the correction. Repeat with B's side to move and r1:7k | r2:2P3r1 | r3:2K5 | r4:8 | r5:8 | r6:8 | r7:8 | r8:1R6; the changed board tests transfer rather than diagram memory.
After the drill, compare your notes with Cut Off King In Rook Endings, Philidor Position, Vancura Defense through the moment to trade the last pawn. Keep A's rejected alternative beside B's chosen line Kc5; this shows whether the conclusion survived a new board signature.
Sources and scope
Sources for Lucena Position: Syzygy tablebase verification reference, 1chess.online editorial scope. Source ids are tablebase, original-analysis. Primary evidence hook: tablebase. Comparisons and practice notes are editorial. Evidence revision: 2026-08-remediation-r2.
Scope note for board pair r1:2Q5 | r2:6k1 | r3:2K5 | r4:5R2 | r5:8 | r6:8 | r7:8 | r8:7r / r1:7k | r2:2P3r1 | r3:2K5 | r4:8 | r5:8 | r6:8 | r7:8 | r8:1R6: this page does not claim that Kh7 is an engine principal variation, that an exact endgame result is verified when the evidence says it is not, or that a tool output replaces human calculation. The conclusion is limited to the recorded boundary and the exception a knight route that changes the blockade.